There is a clinical need for a cost-effective, non-toxic oral therapy to treat Respiratory Syncytial Virus (RSV) infections in young children and immuno ompromised adults. Microbiotix is developing NMSO3, a readily soluble sodium salt of a sulfated sialic acid-lipid. This compound is a potent RSV inhibitor with both oral and parenteral in vivo efficacy in animal model infections. NMSO3 has shown specificity for inhibition of RSV. It is the applicant's aim to prepare an expanded biological profile of this compound as soon as possible so that it might undergo further development as an Investigational New Drug (IND) application candidate. Studies are proposed to define the apparent multi tiered mechanism of action. This will be essential to the development of NMSO3 as an effective therapeutic drug. Microbiotix will also refine the optimum-dosing regimen for treating RSV lung infections in cotton rats, and define the therapeutic index under those dosing conditions. In the Phase II SBIR studies, Microbiotix plans to prepare good manufacturing practice (GMP) quality NMSO3, establish the essential pharmacokinetics and oral bioavailability and the acute toxicity for NMSO3 in cotton rat model. The goal is to file an IND within three years of initiation of the Phase I SBIR studies. [unreadable] [unreadable]